Above 2,500ft Moderate
1,500 to 2,500ft Low
Below 1,500ft Low
Degrees of Avalanche Danger ?
Problem #1: Storm Snow
1-3″ of new snow is expected in this zone Saturday night (3-6″ in the Lutak and Transitional zones). Winds will be light-moderate and southerly at upper elevations, which will wind load the new snow into fresh storm slabs on north aspects. In some areas, these fresh slabs will build up to near 6″ thick, which could cause a hazard in steep or high-risk terrain. The new snow will be sitting on a very weak sandwich of ice crusts and facets, and is not expected to bond well at all.
As heavy snowfall comes in Sunday evening, the danger will rise to Considerable Sunday Night.
Problem #2: Wind Slab
Above 3500ft, snow depths generally range from 30-100cm. In the deeper areas, we have a well-bonded midpack frozen solidly to the ground. It hasn’t been terribly cold so far this year, so facetting between rain crusts has been minor so far. One exception is in high wind-swept areas where the snow is only about 30cm deep. In these areas, there are weak 2-3mm facets at the ground. These areas are more prone to collapsing and extra caution is advised in areas of thin snowpack!
In most deeper areas, the danger is generally Moderate. However, there are thin wind slabs/crusts at the top of the snowpack that are easy to trigger. In high, wind-loaded areas, these upper slabs may be thick enough to cause a serious avalanche, thus pockets of CONSIDERABLE danger probably exist.
Recent Avalanche Activity
The last reported avalanche activity is from the rain-on-snow event on the 18-19th. D1-D3 wet loose and wet slabs came down from the most wind loaded north aspects above 4,000ft. Most of this activity was in the Lutak and Transitional zones where there was more snowpack and more rain.
We had a very wet October, with snow levels about 1,000ft above average, near 3500ft. Above that level there was good accumulation, with almost nothing below it. This trend has continued into November. Looking ahead, expect a weak front Saturday night (3-6″ of new snow), followed by a wet and heavy storm Sunday-Monday (an additional 1″ of precip.). Snow levels should mostly be near sea level if the north wind can hold out for most of the storm, but at some point Monday snow levels will rise up to near 3500ft.
|Snow Depth [in]||Last 24-hr Snow/SWE [in]||Last 3-days Snow/SWE [in]||Today’s Freezing Level [ft]||Today’s Winds||Next 48-hr Snow/SWE|
Mount Ripinsky @ treeline
|5″||0″ / 0.00||0″ / 0.00||0||light, NW||10″/ 1.30 *|
Flower Mountain @ treeline
|7″||0″ / 0.00||0″ / 0.00||0||light, NW||12″/ 1.30 *|
Chilkat Pass @ 3,100ft
|3″||0″ / 0.00||0″ / 0.00||0||light, NW||12″/ 1.00 *|
( *star means meteorological estimate )
Additional Info & Media
If you get out riding, please send in an observation!
Start the season with fresh batteries in your beacon, and do a rescue practice with your partners. Always carry a beacon, shovel, and probe, and KNOW HOW TO USE THEM.
Practice good risk management, which means only expose one person at a time to slopes 30 degrees and steeper, make group communication and unanimous decision making a priority, and choose your terrain wisely: eliminating unnecessary exposure and planning out your safe zones and escape routes.